Effect of exopolysaccharide from Bifidobacterium bifidum on cell of gastric cancer and hTERT
两歧双歧杆菌胞外多糖对胃癌细胞及hTERT的影响

Objective] To study the inhibition of human gastric cancer cell BGC823 by exopolysaccharide (B. EPS) extracted from Bifidobacterium bifidum and the effect on the activity of telomerase rate-limiting factor hTERT. Methods] The B. EPS was divided into three groups by multiplication concentration level which effected on human gastric cancer cell BGC823 in vitro, the inhibition rate of gastric cancer cell BGC-823, the morphology changes of cells and the apoptosis in the initial stage of cell was observed respectively by MTT, inverted fluorescent microscope and the Annexin V-FITC/PI flow cytometry. In addition, the effect of B.EPS on cell telomerase rate-limiting factor hTERT mRNA was tested by RT-PCR; the changes in the concentration of calcium ions inside the cytoplasm were detected by spectrofluorometer. Results] B.EPS inhibited the growth of gastric cancer cell BGC-823 (P<0.05), the inhibition rate increased and the concentration of B.EPS showed dose-time response relation. The expression of cell telomerase rate-limiting factor hTERT mRNA decrease after effected by B.EPS (P<0.05), and showed dose-effect relation. The concentration of calcium ion in cytoplasm was higher than the control apparently (P<0.05). Conclusion] The apoptosis mechanism of human gastric cancer cell BGC823 induced by B.EPS may be relevant with the expression of hTERT mRNA and the concentration of calcium ions in cytoplasm.